Disclosure timing

Disclosure deadlines compared

Last checked 6 November 2026 · 8 sources

Short answer

Disclosure deadlines for listed companies fall into two groups. Some count days. The US Form 8-K is due within four business days of the event ¹, and a Canadian material change report within 10 days ⁴. Others use a standard. EU and UK MAR say as soon as possible ^3,8, ASX says immediately, read as promptly and without delay ⁵, and Hong Kong says as soon as reasonably practicable ⁶. Singapore's Catalist rules say an issuer must announce price-sensitive information ⁷.

United States: Form 8-K within four business days ¹
European Union: As soon as possible, MAR Article 17(1) ³
United Kingdom: As soon as possible, UK MAR Article 17(1) ⁸
Canada: News release immediately, report within 10 days ⁴
Australia: Immediately, read as promptly and without delay ⁵
Hong Kong: As soon as reasonably practicable ⁶

Fixed clocks and open standards

A fixed clock gives a set number of days from a trigger. The US and Canada use this model for their formal reports ^1,4. An open standard uses words such as as soon as possible or immediately. The EU, the UK, Australia and Hong Kong use this model for inside or price-sensitive information ^3,8^5,6.

Even under an open standard, the meaning is not instant. ASX guidance says immediately should not be read as instantaneously, but as promptly and without delay ⁵. Hong Kong guidance says as soon as reasonably practicable means the company should immediately take all steps needed in the circumstances, such as confirming facts and assessing impact ⁶.

Deadlines side by side

Jurisdiction	Rule	Trigger	Deadline
United States	Form 8-K ¹	Reportable event, such as a material definitive agreement ¹	Four business days ¹
United States	Form 8-K Item 1.05 ¹	Determination that a cyber incident is material ¹	Four business days after the determination ¹
United States	Regulation FD ²	Non-intentional selective disclosure ²	Later of 24 hours or start of next day NYSE trading ²
European Union	MAR Article 17(1) ³	Inside information directly concerning the issuer ³	As soon as possible ³
United Kingdom	UK MAR Article 17(1) ⁸	Inside information directly concerning the issuer ⁸	As soon as possible ⁸
Canada	NI 51-102 section 7.1 ⁴	Material change ⁴	News release immediately, report within 10 days ⁴
Australia	ASX Listing Rule 3.1 ⁵	Information with a material effect on price or value ⁵	Immediately ⁵
Hong Kong	SFO section 307B ⁶	Inside information comes to the corporation's knowledge ⁶	As soon as reasonably practicable ⁶
Singapore	Catalist Rule 703 ⁷	Information needed to avoid a false market or likely to materially affect price ⁷	Must announce, no day count in the rule text ⁷

Exceptions and delay

Most systems allow some information to be held back for a time. Each one sets its own tests.

EU and UK MAR allow delay on the issuer's own responsibility if disclosure would prejudice legitimate interests, delay would not mislead the public and confidentiality can be kept ^3,8.
Canada allows a confidential material change report where disclosure would be unduly detrimental, filed with written reasons ⁴.
ASX Listing Rule 3.1A exempts information only if it falls in a listed category, is confidential and a reasonable person would not expect it to be disclosed ⁵.
Singapore Catalist Rule 703(3) uses three similar conditions, including information about an incomplete proposal or negotiation ⁷.
US Item 1.05 allows delay where the Attorney General finds a substantial risk to national security or public safety ¹.

Other clocks in the same rule books

Event disclosure is not the only deadline. Under EU MAR Article 19, managers must notify their own dealings no later than three business days after the transaction, and the issuer must publish them within two business days of receipt ³. In Hong Kong, Part XIVA of the Securities and Futures Ordinance took effect on 1 January 2013, which put the inside information duty on a statutory basis ⁶. In Australia, ASX guidance says Listing Rule 3.1 has statutory force under section 674 of the Corporations Act 2001 ⁵.

Reading the dates in practice

When comparing two companies in two markets, do not compare the number of days alone. Note what starts each clock. In Canada it is the date the change occurs ⁴. Under US Item 1.05 it is the materiality determination ¹. Under MAR it is the moment information becomes inside information ³. The date tools on this site list these rules with their sources.

Common questions

Which market has the shortest disclosure deadline?

Rules use different triggers, so a direct ranking can mislead. The US uses four business days ¹. The EU, UK, Australia and Hong Kong use standards such as as soon as possible ^3,8^5,6.

Does immediately mean instantly under ASX rules?

No. ASX guidance reads immediately as promptly and without delay ⁵.

How long does a Canadian issuer have to file a material change report?

As soon as practicable and in any event within 10 days of the date on which the change occurs ⁴.

When did Hong Kong's statutory disclosure duty start?

Part XIVA of the Securities and Futures Ordinance took effect on 1 January 2013 ⁶.

Rules and charges change. Check the official source linked on this page before you pay or travel. Spotted an error? Email hello@datedrecord.com.

Sources

Form 8-K timing explained
How the US Form 8-K four business day clock works, when it starts, what the cover page date means and how EDGAR decides the filing date.
MAR inside information timing explained
How EU and UK MAR time the disclosure of inside information, when delay is allowed and what changed for protracted processes in 2026.
Event date versus disclosure date
Why official records carry two dates, the day something happened and the day it was made public, with examples from the US, EU, Canada and Australia.
How to build a sourced timeline
A method for building a timeline from filings, laws and statistics: which date to record, how to write it, and how to cite the version you read.